1. Field of the Invention
The present invention is generally related to a connection system for connecting two or more marine propulsion devices together and, more particularly, to a system that simplifies and strengthens a tie bar system for operating two or more outboard motors in tandem.
2. Description of the Prior Art
It is well known by those skilled in the art that two or more marine propulsion devices can be used in tandem on a marine vessel. When two or more outboard motors are used in this manner, a tie bar or connecting link is used to connect the outboard motors together so that they can be steered in tandem to allow the marine vessel to be maneuvered with both marine propulsion devices operating cooperatively.
U.S. Pat. No. 6,406,340, which issued to Fetchko et al. on Jun. 18, 2002, describes a twin outboard motor hydraulic steering system. The steering assembly applies a force to tiller arms of twin marine, outboard propulsion units and rotates the propulsion units about a steering axis between a center position and hard over positions to each side of the center position. Each propulsion unit is supported for arcuate movement about a tilt axis which is generally perpendicular to the steering axis. There is a hydraulic steering apparatus mounted on a first of the propulsion units which includes a hydraulic cylinder pivotally connected to a member which is pivotally mounted on the tiller arm of the first propulsion unit. A tie bar is pivotally connected to the steering apparatus and pivotally connected to the tiller arm of a second propulsion unit. For example, the tie bar may be pivotally connected to the steering apparatus by a ball joint connected to the steering apparatus by a bracket which moves with the member.
U.S. Pat. No. 4,836,812, which issued to Griffiths on Jun. 6, 1989, discloses a steering system for an auxiliary marine engine. The steering system for controlling an auxiliary marine engine includes an auxiliary engine steering cable operably connected to the hydraulic cylinder of the steering system for the primary engine so that linear movement of the hydraulic cylinder results in movement of the steering cable and pivotal steering of the auxiliary engine.
U.S. Pat. No. 4,731,035, which issued to Wagner on Mar. 15, 1988, describes a steering mechanism for outboard motors. The mechanism is disclosed for a boat equipped with an outboard motor. The steering mechanism has a pair of opposed single acting cylinders maintained in a spaced relationship by a frame member. A pair of brackets enables pivotal connection of the steering mechanism with the mounting bracket of the motor. A piston is received in and extends between the cylinders and carries a lost motion linkage connectable with the tiller arm of the motor to induce steering movement of the motor upon actuation of the piston.
U.S. Pat. No. 6,561,860, which issued to Colyvas on May 13, 2003, describes a maneuvering enhancer for twin outboard motor boats. An adjustable length bar is used to replace the rigid bar, the one connecting the two outboards or the two outdrives of a boat, for steering purposes. The adjustable bar is electrically operated through a switch on the boat's dashboard, the switch having two operating positions. One position is to keep propellers creating two parallel thrusts and a second position is to shift the propellers to create a vee configuration, by which the boat's maneuverability will be enhanced.
U.S. Pat. No. 4,009,678, which issued to North on Mar. 1, 1977, discloses a multiple push-pull cable transmission apparatus. A racing boat is powered by a pair of pendent inboard-outboard drive units having inboard steering arms. A pair of push-pull cable units connect a forward located steering wheel unit to the arms. The cable units extend along opposite sides of the boat with the casing fixed at the steering wheel and the core wires secured to the opposite sides of the steering wheel and to the opposite steering arms. A power steering unit coupled to the one steering arm has an input element. The adjacent cable unit has a threaded extension pipe with a fixed coupler connected to the power control input. A core rod is connected to the core and is slidably mounted in the pipe and is pivotally connected to the power steering link to transmit casing reaction forces to the power input. An adjustable rigid linkage includes a tie rod having adjustable ends pivotally connected to the anchor member on the extension pipes. The anchor member of the second cable unit is slidably mounted in a pivotally mounted support for generally linear movement. The rod directly interconnects the two anchor members to each other and to the power input for rapid power steering response. A second adjustable tie rod is pivotally connected to the arms and the core wires and is set to properly locate the steering arms.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.
Known tie bar systems for tandem steering of two or more outboard motors typically exhibit two inherent problems. First, adjusting the various elements of the system during installation can be exceedingly difficult when using known tie bar systems. In addition, the structure of the individual joints, about which the various linkages rotate, can place the components under undue stress because of the lack of alignment between certain forces and their reactions. It would therefore be significantly beneficial if a tandem outboard motor steering system could be provided which is easier to assemble and adjust than known systems and which directs reactive forces in alignment with original forces to avoid creating moments that can otherwise be destructive to individual components.